Method of air conditioning



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BY KIM-fp@ ATTORNEYS Martell [lm W. W. CUMMINGS METHOD OF AIRCONDITIONING Filed March 24, 1949 Patented Oct. 5, 1954 UNITED STATESPATENT OFFICE 3 Claims.

This invention relates to improvements in methods of air conditioning,and has for its object to increase the capacity of standardrefrigeration systems without materially adding to their operatingcosts.

In the standard refrigeration system used for cooling air, for instance,as is well known, the refrigerant in low pressure gaseous form, of anystandard and known type, is rst compressed by a standard compressor to agas of high pressure. This compression of the gas generates heat. Thehigh pressure gas then passes to the condenser, where it is condensed,or changed to liquid form through the use of a cooling medium, which isfrequently cold water, and some times air, and in the condensationprocess the high pressure gas loses heat and the cooling medium gainsheat. The heat thus acquired by the cooling medium is normally wasted.The high pressure saturation refrigerant then usually passes to areceiver or storage tank, from which it is released through an expansionor regulating valve to an evaporating coil, Where the liquid refrigerantchanges back to a gas of low pressure. In this process the refrigerantdrops rapidly in temperature and there is an exchange of heat betweenthe refrigerant and a cooling medium, which may be brine, which in turnis recirculated about the area being refrigerated. Or the exchange ofheat may be between the refrigerant in the evaporating coil across whichair is passed to be cooled, or it may be the substance beingrefrigerated itself which loses heat to the refrigerant. The gas is thenagain compressed as before and the cycle is repeated.

Heretofore, the only practical way of materially increasing the capacityof such a standard refrigeration system has involved increasing thephysical facilities, as by duplicating the existing plant or byreplacing it with one of greater capacity. This of necessity hasinvolved increasing the operating costs, or doubling them, if the plantis duplicated. I have discovered, however, that the capacity of thestandard refrigeration system may be greatly increased or even doubled,without materially increasing the operating costs, by combining with ita uid sorbent system (such as triethylene glycol, or lithium chloride)for dehumidifying the air, and regenerating the sorbent, by using theliquid sorbent, after passing through the dehumidifier, as the coolingor condensing medium for the refrigerant. At the same time, the sorbent,which has thus gained heat in the condensing process, can be used forpreheating the air stream in the sorbent regeneration system forregenerating or restoring the sorbent by extracting from it the moisturepreviously absorbed from the air in the dehumidication process. The airstream in the uid sorbent regeneration system is normally separatelyheated from an outside or additional heat source. The heat thus normallythrown away on the refrigeration side is thus utilized for preheatingthe air stream in the sorbent regeneration cycle, and as the heatnormally thrown away on the refrigeration side usually equals thatrequired for sorbent regeneration (per yton of accomplishment) greatsavings in operating costs can be achieved. Thus for any desiredrefrigeration tonnage, by thus combining the standard refrigerationsystem with a uid sorbent regeneration system, the refrigeratingcapacity can be doubled, without appreciably increasing the operatingcosts, in either power or water consumption. When the uid sorbentregeneration system also includes the use of a diffusing tower, asdescribed in my copending patent application Serial No. 63,358, filedDecember 3, 1948, now abandoned, where the warm high vapor pressure airis passed through the diffusing tower and equalization of the vaporpressure to that of the surrounding atmosphere is elected, withconsequent loss of water vapor without appreciable loss of heat,additional savings in operating costs can be achieved.

In the drawings:

The iigure is a diagrammatic showing of my invention, in which astandard refrigeration system is combined with a fluid sorbentregeneration system.

As shown in the drawings, A represents the standard refrigeration systemor cycle, and B represents the sorbent regeneration system or cycle. Inthe refrigeration system of standard form the compresser unit isindicated at l0, where the low pressure saturated gas of a refrigerant,of any well known type such as Freon 11 or 12 (which chemically isdichloro-difiuoro-methane, CClzFz) is compressed to a high pressuresaturated gas, and in the process heat is generated. A condenser unit isindicated at I2, and again is of standard type, where the high pressureSaturated gas of a superheated temperature is cooled and condensed to ahigh pressure saturated liquid. The usual cooling medium is, of course,-cold water and occasionally air, which is passed through a heatexchanger, whereby the heat of the high pressure saturated gas isremoved and carried away by the cooling medium. The heat thus acquiredby the cooling medium in the condensing processis normally wasted. Anovel feature of the present invention, however, is that the diluteliquid sorbent from the dehumidifying unit 20 in the sorbentregeneration system B is used as the cooling or condensing medium in thecondenser I2 of the refrigeration system A. The high pressure saturatedliquid refrigerant then passes to the receiver or tank I4, where it isretained until it passes through the expansion valve I5. In passingthrough the expansion valve l5 the high pressure liquid refrigerantpasses to the evaporator or cooler i6 and expands to a low pressure gas.is required, and as well known, the heat is drawn from the substances tobe cooled; which may be of any nature, and where the evaporator orcooler IB is located at a distance from the substance to be cooled,brine, ammonia, cold water. or other suitable cooling medium is nrstcooled in the evaporator I6 and then pumped to the cooling chamber as incentral refrigeration plants.

As previously stated; the sorbent regeneration system B- is connected tothe refrigeration system A through utilizing the-dilute liquid sorbentfrom the dehumidier 2G as the cooling medium in the condenser l2` of therefrigeration system A. The sorbent regeneration system B may be of anystandardl type, but for greatest emciency the form shown inthe drawingsat B- is preferred. It will be understood that the Warm moist air passesthrough the dehumidier 2e which takes-out'most of` the moisture andremoves latent heat or heat of the moisture from the air. The warm dryair may then beV passed through a cooling coil 22 which receives coolingmedium through the pipe I- from the evaporator or cooler i6 and whichcooling medium is then returned to the cooler I6A through thepipe I9.Passing the warm dry air through the-coolingV coil 22 removes aportionof the sensible heat content of that air. The cool dry air then passesintothe controlled zone. By thus combiningthe-sorbent' regenerationsystem BA with the refrigeration system-A, the latent heat removal isaccomplished in great part by the use of heat formerly wasted.

The sorbent regeneration system B rst conducts the concentrated liquidsorbent, of any standardl or suitable type, such as triethylene glycol,lithium chlorideY and the like, to the dehumidier 2d through the conduitl-B. As is Well known an air stream is forced through the dehumidifier2t' by a fan (not shown), where it passes through' a spray or cascade oftheA concentrated sorbent which absorbs moisture from the air stream,thus dehumidifying it. Asprevi'- ously stated, liquid sorbent thusdilutedis conducted through'the condenser l2 of the refrigerationsystemA A, where it acts as the cooling medium for the refrigerant inlthe condenser l2. Inthe process the dilute liquid sorbent acquiresconsiderable heat, and it is then conducted to the'pre-heat exchanger 24in the air stream 26 of the closed sorbent regeneration system B. Thediluteliquid sorbent there gives up its heat to thev air stream andVthus preheats the latterfor subsequent use. The sorbent may be furthercooled in the sorbent cooler 2B, which is cooled by anyv suitablecooling medium, chilled Water or the like, or from the cooling medium ofthe evaporator or cooler I6 of the refrigeration cycle A. The sorbentcooler 28, however, may be omitted entirely if the sorbent issufficiently cooledwithout it, and the cooled dilute sorbent then passesto the spray nozzle 3U, where the sorbent is regenerated and themoisture extracted. from it by passing the heated. air stream fromconduit 26 During this change of state heat.

4 through the spray of the dilute sorbent. The regenerated andconcentrated sorbent then passes again through pipe I8 back to thedehumidier 20. The heated moisture containing air after passing throughthe spray Sil may then be wasted to atmosphere where its heat isentirely lost. But I prefer to conduct it through conduit 32 to thediirusing tower 34 having porous, permeable or pervious walls 35. Theside Walls. 3.5 of the diffusion tower are made of" a porous, permeableor pervious material, relatively densely packed but having fineinterstices therethrough which permits the moisture content in the air,in vapor or gaseous form and or" relatively high vapor pressure toescape through the walls 35, until the vapor pressure within thediiusion tower 34 equalizes withy that of the air surrounding the towerse. The interstices or passages through the Walls 35 are so small thatthey oier frictional resistance to the passage of air therethrough bothfrom the' inside out and from the inside in. The walls 35 thusvineiectact as a lter in permitting the high pressure watervapor to escape, butretaining the relatively low pressure heated air therein. The lteredwalls- 2li may be made of any suitable material, which is preferablyrustless, and will not absorb or soak up moisture, such as spun glass,or fine metal wire wool such as stainless steel, copper or brass. Thesorbent regeneration system B', with its diffusing tower 3G is morefully described' in my copending application Serial No. 53,358, filedDecember, 3, 194:8. By conductingv the heated and moisture containingair through my diffusion tower 3ft, at least fifty percent of the heattherein normally lost ii exhausted toatmosphere, can be saved by themethod and apparatus embodying my sorbent regeneration system B anddisclosed in my above mentioned patent application. The air stream witha large portion of its moisture content removed is then re-circulatedthrough the closed sorbent regeneration system B by means of thecirculating fan 3S, where the' air is again passed through the preheatexchanger 24, to repeat the sorbent regeneration cycle. It will thus beseen that by utilizing the warmed dilute liquid sorbent after passingthrough the condenser |25 of the' refrigeration system A, to preheat theair in the closed sorbent regeneration system B, no separater oradditional heat source is necessary for preheating the air, as isrequired in a standardsorbent regeneration system.

It will thus be seen that by combining a standard refrigeration systemwith a liquidV sorbent regeneration system the capacity ofl a standardrefrigeration system, the refrigeratingv capacity can be doubled,without materially increasing the operating costs, either in power orwater consumption.

I claim:

1. The process of air conditioning which combines cooling anddehumidifying the air in a controlled area which consists in' combininga refrigeration system for cooling the air wherein a refrigerant in gasform is compressed to high pressure, and then condensed to liquid formIwith a liquid sorbent regeneration system for dehumidifying the air,and' usingthe dilute liquid sorbent from the dehumidifier of thecontrolled air stream in the liquid? sorbent regeneration system as thecooling medium for condensingv the refrigerant inthe refrigerationsystem, and using ther dilute; liquid. sorbent as. heatedi in condensingthe refrigerant in: the refrigeration system'V for preheating the airstream usedzin regenerating the liquid sorbent in the liquid sorbentregeneration system.

2. The process of air conditioning which combines cooling anddehumidifying the air in a controlled area which consists in combining arefrigeration system for cooling the air wherein a refrigerant in gasform is compressed to high pressure, and then condensed to liquid form,with a liquid sorbent regeneration system for dehumidifying the air, andusing the dilute liquid sorbent from the dehumidifier of the controlledair stream in the liquid sorbent regeneration system as the coolingmedium for condensing the refrigerant in the refrigeration system, usingthe dilute liquid sorbent as heated in condensing the refrigerant in therefrigeration system for preheating the air stream used in regeneratingthe liquid sorbent in the liquid sorbent regeneration system, andregenerating the dilute liquid sorbent by passing said preheated airstream through it.

3. The process of air conditioning which combines cooling anddehumidifying the air in a controlled area which consists in combining arefrigeration system for cooling the air wherein a refrigerant in gasform is compressed to high pressure, and then condensed to liquid form,with a liquid sorbent regeneration system for dehumidifying the air, andusing the dilute liquid sorbent from the dehumidifier of the controlledair stream in the liquid sorbent regeneration system as the coolingmedium for condensing the refrigerant in the refrigeration system, usingthe dilute liquid sorbent as heated in condensing the refrigerant in therefrigeration system for preheating the air stream used in regeneratingthe liquid sorbent in the liquid sorbent regeneration system, andregenerating the dilute liquid sorbent by passing said preheated airstream through it. and conducting the heated air stream through anequalizer chamber exposed on its outer surface to normal atmosphericpressure and having porous walls permeable to the passage of highpressure water vapor in said preheated air stream, but resistant to thepassage of air therethrough.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,937,984 Scherer Dec. 5, 1933 1,943,908 Woods Jan. 16, 19342,223,586 Thomas Dec. 3, 1940 2,269,053 Crawford Jan. 6, 1942 2,355,828Taylor Aug. 15, 1944 2,421,121 Haagen-Smit May 27, 1947

